/Engine/Source/Editor/UnrealEd/Public/FbxImporter.h
Tries to find an existing UnrealMaterial from the FbxMaterial, returns nullptr if could not find a material. The function will look for materials imported by the FbxFactory first, and then search into the asset database using the passed MaterialSearchLocation search scope.
The UMaterialInterfaceFound, returns nullptr if no material was found.
[UMaterialInterface](API\Runtime\Engine\Materials\UMaterialInterface) * FindExistingMaterialFromFbxMaterial ( const FbxSurfaceMaterial & FbxMaterial, EMaterialSearchLocation MaterialSearchLocation )